Upright vacuum cleaners employ a variety of dirt separators to remove dirt and debris from a working air stream. Some dirt separators use one or more frusto-conical-shaped separator(s) and others use high-speed rotational motion of the air/dirt to separate the dirt by centrifugal force. Typically, working air enters and exits at an upper portion of the dirt separator as the bottom portion of the dirt separator is used to collect debris. Before exiting the dirt separator, the working air may flow through an exhaust grill. The exhaust grill can have perforations, holes, vanes, or louvers defining openings through which air may pass.
A dirt collector can be provided for collecting the removed dirt from the working air stream, and can be separate or integral with the dirt separator. In vacuum cleaners where the dirt separator and collector are integral, the entire separator/collector assembly can be removable from the vacuum cleaner for emptying collected dirt. In some cases, a bottom wall of the dirt collector serves as a dirt door, and is provided with a release mechanism for opening the dirt door to empty the accumulated contents.
Some cyclonic dirt separators have two separation stages, and use a dirt collector with individual chambers for receiving dirt separated at each stage. In one design, dirt from the second or downstream separation stage is collected within a centrally-located tube that meets the bottom wall of the dirt collector that serves as the dirt door.